Insulating electric conductor.



No. 666,004. Patented Jan. l5, l90l. W. L. R. EMMET.

INSULATING ELECTRIC CONDUCTOR.

(Application filed Aug. 19, 1899.) (No Model.)

Fig. 2.

Fig.3.

Jnventoh \mlliam L R. Emmet.

UNITED STATES PATENT Quince.

\VILLIAM. L. R. EMMET, OF SCIIENEOTADY, NEW YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NE YORK.

ENSU LATING ELECTRIC GUN BUG FUR.

SPECIFICATION forming partoi Letters Patent No. 666,004, dated January 15, 1901.

Application filed August 19, 1899. serial No. '72 7,743. (No model.)

to (til whom it may concern: ing formed of a plurality of laminae in the Beitknown thatI,\VILLIAM LE ROY EMMET, manner hereinafter set forth. a citizen of the United States, residing at My invention therefore comprises a con- Schenectady, in the county of Schenectady ductor provided with a plurality of layers of 55 and Slate of New York, have invented ceran insulating compound applied in a soft contain new and useful Improvements in lnsudition and permitted to oxidize and harden lating Electric Conductors, (Case No. 1,370,) in situ.

of which the following is a specification. Other features of novelty will he more fully The object of the present invention is to described hereinafter and will be definitely 6o 10 provide an improved insulation for electric indicated in the claims.

conductors or groups of conductors which In the accompanying drawings I have eX- will render them proof against damage from emplified a few of the uses to which my inmoisture or moderate degrees of heat. vention may be applied.

In carrying out the invention 1 provide an Figure 1 shows in magnified section an elec- 65 I5 insulating-covering composed of a plurality tric conductor made in accordance with my of layers or coats of an insulating compound invention; Fig. 2, a group of conductors repsuccessively applied and permitted to harden resenting an armature-coil for an electric mo before the nextsucceeding coatis made. The tor or dynamo-electric machine, and Fig. 3 several coats may he applied by dipping or shows a modified form of insulation. 70

leading the conductor to he treated through a The instances herein illustrated of the apbath of the insulating compound or by application ofinyinvention are, however,merely plying the compound with a brush or in any typical, as it may be applied to any case in other suitable way, so as to produce a series which a conductor is desired to have high inof layers. sulating properties and is to be rendered proof 75 My invention is not restricted to the appliagainst damage by moisture overalongperiod cation of anyparticularinsulatingcompound; of service. but I prefer to employ a compound contain- As shown in the drawings, 1 represents an ing a vegetable oxidizable oil which may be electric conductor. A plurality of independrendered fluid by heat or may he thinned by ent coats or layers of insulating compound, 80

a solvent. A compound which yields excelas shown at 2 3 4-, are successively applied. lent results may be composed of about eighty The application may be made by carrying the parts of boiled linseed-oil and twenty parts conductor through a bath of insulating comof rosin. If applied cold, this may be thinned pound rendered fluid or sufficiently plastic by a solvent, such as benzin, to the desired for working by heat or by a solvent and then 85 5 consistency and applied to the conductor in given sufficient time to harden or dry out beany suitable way. After coating, the confore the next coat is applied. Ihave attained ductor is left until the compound hardens or the best results by employing a mixture of the solvent evaporates, after which a second boiled linseed-oil and rosin thinned to the coat is similarly applied, and then in order proper consistency with benzin, the linseed- 0 a third or as many coats as may be necessary oil and rosin being mixed in about the profor the particular use to which the conductor portions of four to one. is to be put. By applying the coats in the manner speci- In insulating coilsI prefer to cover the coils fled a closely-coherent protective coating is With a layer of some textile fabricsuch, for produced, the several layers becoming inti- 5 example, as muslin or other flexible non-conmately associated without definite line of deducting material having a tough structure marcation and effectively protecting the conwhich will increase its durability and render ductor against access of air. The manner of it proof against abrasion, and then apply the applying the coats also precludes the formasuccessive coats to the covering. Any numtion of air-bubbles, and thereby enhances the I00 her of layers of such a covering may be apvalue of the insulation to a far greater deplied, each provided with an insulating-coatgree than is otherwise possible. The desired thickness of insulation being built up on the conductor after permitting the inner stratum to harden, a uniform dense tough coherent covering is assured. The exposure of each coat to the air before the next is applied oxidizes the vegetable-oil,givingit toughness and density, and affords a firm foundation for the next layer, which strongly adheres to it without softening it. Suificient depth of the compound should be applied by the successive coats to at least insure a complete embedding of the fine fibers projecting from strands of the textile material, which if exposed reduce the insulating power of the covered conductor. In insulating the conductor-a textile or flexible fabric may be employed as a foundation for the insulating compound, in Fig. 1, or for some uses the successive coats may be applied directly to the metal, as in Fig.

in Fig. 2 an example of an armaturecoil to which my invention has been applied is shown. The group of conductors forming the coil may be provided with ordinary insulation and filled in the interstices between the adjacent conductors with an insulating compound, as shown, and then wrapped with a textile fabric, such as muslin, and provided with a series of layers or coats of insulation in the manner specified. This may be conveniently effected by dipping the coil or by painting the compound in successive layers upon the textile covering, sufficient time being allowed between the layers for the film or coat to harden and oxidize. One or more layers of textile fabric thus treated may be applied until a sufficient depth to provide the desired insulation and wearing qualities is attained. A conductor or coil so treated not only stands very high potentials, but does not deteriorate over long periods of service and under severe conditions even under heat. Conductors so treated have been subjected to a temperature of 7 5 eentigrade for six months without material alteration. It does not fuse if the conductor heats, as other compounds commonly employed, and is entirely unaffected from ranges of temperature such as insulated conductors are ordinarily subjected to. The tough dense layer of oxidized oil not only prevents abrasion under strains or by bending by its elasticity, but by reason of its mode of application defies access of moisture to the conductor.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. An insulated electric conductor covered with a plurality of closely-coherent layers of oxidized insulating solution, each layer being coherently connected to the other as described.

2. An. insulated electric conductor covered with a plurality of films of an infusible insulating material applied in solution, said films closely cohering each to the other.

3. An insulated electric conductor covered with a plurality of layers of porous fabric, each layer being covered with a plurality of independentclosely-coherent films of an infusibleinsulating compound each layer being a residue of a solution.

4. An insulated electric conductor covered with a plurality of layers of textile fabric, each of which is provided with a plurality of independent coats of closely-coherent infusible insulating compound each layer being a residue of a solution.

5. An insulated electric conductor covered with a plurality of independent layers of oxidized oil, the several layers being closely-coherent residues of a solution.

6. An insulated electric conductor covered with a plurality of layers of textile fabric, each provided with several independentfilm residues of a solution of hardened oxidized oil closely coherent to one another.

In witness whereof I have hereunto set my hand this 17th day of August, 1899.

YVILLIAM L. R. EMMET.

\Vitnesses:

BENJAMIN B. HULL, EDWARD WILLIAMs, Jr. 

